Methods of fixing ink

ABSTRACT

The invention provides methods for providing improved image quality and water resistance of dye based ink images on substrates using aqueous dispersed mordants and dispersed hydrophobic materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.09/778,475, filed Feb. 7, 2001, now U.S. Pat. No. 6,764,725; which is acontinuation-in-part of U.S. application Ser. No. 09/500,153, filed Feb.8, 2000, now abandoned.

FIELD OF THE INVENTION

The present invention relates to ink fixing materials and methods forfixing dye based inks to solid and porous substrates, for example, wallsand fabrics.

BACKGROUND OF THE INVENTION

Direct inkjet printing onto a variety of substrates such as films,papers, and fabrics has been used to generate graphic images. However,for substrates that are either of poor dimensional stability (such asmany fabrics), or that are too large to be handled using a conventionalinkjet printer (for example, a wall of a room), indirect printingmethods such as transfer printing methods are normally employed. Currentinkjet transfer printing methods include printing onto fabrics that haveadhesive backings adhering them to a release liner, or iron-ontransfers.

Inkjet printing has been used to provide images on a wide variety ofsubstrates including films, papers, fabrics, and the like. Commerciallyavailable inks for ink-jet printers are typically aqueous based andemploy dyes as colorants. Current commercially available inks generallylack the simultaneous properties of good image quality (e.g., highresolution and color density) and waterfastness or washfastness whenprinted on any of the above-mentioned substrates. This is important ifthe image is transferred to a surface that will encounter water or bewashed in normal usage (for example, clothing, room walls, etc.).

Whether inkjet printing is performed in an industrial process or on aprinter attached to a personal computer, there exists a need to be ableto print an image on a wide variety of substrates that have thesimultaneous properties of good image quality and waterfastness or evenwashfastness.

SUMMARY OF THE INVENTION

The present invention provides compositions and processes useful forimproving image quality and water resistance of dye based ink images,particularly dye based inks used in inkjet printing. The compositionsand processes are easy to use and suitable for office and home useenvironments.

In one aspect, the invention provides a method for providing a durableink image on a substrate. The method comprises the steps of coating asurface of the substrate with an aqueous mordant dispersion; printing ortransferring a selected image onto the coated surface; optionally dryingthe image; applying a dispersed hydrophobic material onto the imagedsurface; and drying the dispersed hydrophobic material. The method mayoptionally further include the step of heating the transferred and fixedimage. The method may also optionally include the step of drying thecoated mordant dispersion before printing or transferring the image.

In another aspect, the invention provides another method for providing adurable ink image on a substrate. The method comprises the steps ofcoating a surface of the substrate with an ink fixing mixture comprisingan aqueous dispersion of a mordant and a dispersed hydrophobic material;printing or transferring a selected image onto the coated substrate; anddrying the image and coated ink fixing mixture. The method may furtherinclude the step of heating the transferred and fixed image.

In another aspect, the invention provides a method for providing adurable ink image on a non-porous substrate. The method comprises thesteps of coating a surface of a non-porous substrate with an aqueousfluoropolymer dispersion, printing or transferring an image onto thecoated non-porous substrate; and heating the coated image. The methodmay also optionally include drying the coated fluoropolymer dispersionat ambient temperature prior to printing or transferring the image.

In still another aspect, image bearing articles are provided that areprepared by any of the preceding methods.

In still an another aspect, the invention provides a kit for providing adurable image on a substrate. The kit comprises an image transfermedium, aqueous mordant dispersion, and hydrophobic material dispersion.The mordant dispersion and hydrophobic material dispersions may besupplied separately or as a mixture of the two.

A feature of the invention is that it provides materials and meanswhereby aqueous inkjet inks may be printed with high resolution and goodcolor density, and having improved waterfastness and washfastnesscompared to prior methods.

The term “mordant” means a compound which, when present in acomposition, interacts with a dye to prevent diffusion through thecomposition.

A “non-porous substrate” is a substrate that is not porous to ink.

As used herein, the term “dry” refers to dry to the touch; that is, doesnot transfer to a finger when touched.

BRIEF DESCRIPTION OF THE FIGURES

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

FIGS. 1-14 are magnified digital images of images prepared usingexamples of the invention and comparative examples.

FIGS. 15-18 show magnified illustrative views of useful image transfermedia.

DETAILED DESCRIPTION OF THE INVENTION

The invention in its various aspects employs two essential components: amordant, and a dispersed hydrophobic material. The mordant functions toimprove wettability of the substrate, and improves image quality byhelping to fix the image. The dispersed hydrophobic material serves toprovide a degree of durability and water resistance and washfastness tothe printed image.

Suitable mordants are readily dispersible or soluble in water andinclude polymeric dye mordants which may be cationic or neutral,inorganic metal ion containing colloids, and polymer bound metal ioncontaining colloids.

Polymeric dye mordants include those known in the art for use with dyebased inks, for example, quaternary ammonium groups containing polymerssuch as poly(ethyleneiminium) chloride; poly(vinylpyridinium) chloride;poly(N,N-diallyldimethylammonium) bromide; poly(ethyleniminium)chloride; copolymers having quaternary ammonium groups such as thosedisclosed in U.S. Pat. No. 5,712,027 (Ali), U.S. Pat. No. 5,354,813(Farooq), and U.S. Pat. No. 5,342,688 (Kitchin), all incorporated byreference herein; epichlorohydrin/aminopolymer resins (for example“KYMENE 557H”, commercially available from Hercules, Inc. of Wilmington,Del.); poly(ethylenimine); polyaziridine condensation products;homopolymers and copolymers of N-vinylpyrrolidone, for example,copolymers of N-vinylpyrrolidone and dimethylaminoethyl methacrylate;copolymers of N-vinylpyrrolidone and methylvinylimidazolium salts;homopolymers and copolymers of acrylamide; homopolymers and copolymersof N,N-dimethylacrylamide; homopolymers and copolymers ofN,N-diallylmethylamine; and condensates of aminoalkylsilanes, such as3-aminopropyltriethoxysilane, N,N-diethyl-3-aminopropyltriethoxysilane,etc.

Non-limiting examples of inorganic metal ion containing colloids includeinorganic sols such as alumina colloids, silica colloids,aluminosilicate colloids; and surface treated silica and aluminacolloids that have been surface treated with, for example, alumina, oran organosilane (such as aminopropyltriethoxysilane, etc.).

Non-limiting examples of polymer bound metal ion containing colloidsinclude aluminum salts of organic polymers such as hydroxypropylmethylcellulose crosslinked with aluminum ions as described in U.S. Pat.No. 5,686,602, incorporated by reference herein.

The mordant is applied to the substrate as a 1-50 weight percentsolution, preferably 15-30 weight percent solution in water, and thenoptionally dried prior to imaging.

Dispersed hydrophobic materials serve to provide an aqueous source ofhydrophobic materials that may be applied to printed images to enhancetheir waterfastness and washfastness. While dispersed (e.g.,emulsified), the hydrophobic materials are not effective protectiveagents (not hydrophobic), but upon drying, these materials often becomehydrophobic. Thus, it is possible to print directly onto substratestreated with hydrophobic materials using aqueous inks so long as thehydrophobic materials have not yet become hydrophobic. “Hydrophobic” asused herein means that the surface of the material is not readily wettedby water. However, once the emulsions are hydrophobic (for example, byheating after air drying) the printing process is generally difficult tocarry out successfully with aqueous inks. Any hydrophobic material knownin the art that can be dispersed may be used in practice of theinvention. Preferred dispersed hydrophobic materials are fluorinatedorganic compounds, silicones, polyvinyls, polyesters, and polyurethanes.Fluorinated organic compounds are most preferred as hydrophobicmaterials.

Fluorinated organic compounds useful in practice of the presentinvention include aqueous fluoropolymer dispersions that, when dried,form a surface that is repellent to water. Importantly, fluorinatedsurfactants, by their nature, generally do not provide such repellency.Examples of fluoropolymer dispersions that are useful in practice of theinvention include those sold under the FLUORAD trade designation byMinnesota Mining and Manufacturing Company of St. Paul, Minn., such asFLUORAD FC-359 (an aqueous dispersion of a fluoroalkyl polymer(approximately 20 percent)), FLUORAD FC-461 (an aqueous dispersion of afluoroalkyl copolymer (approximately 27 percent), FLUORAD FC-1355 (anaqueous dispersion of a fluoroalkyl polymer (approximately 15 percent)),FLUORAD FC-405 (a fluoroaliphatic silyl ether approximately 62 percent,ethanol approximately 37 percent, 2-butanone approximately 1 percent)and FLUORAD FC-280 (an aqueous dispersion of a fluoroalkyl polymer(approximately 30 percent)).

Non-limiting examples of useful silicones include polysiloxane polymers(such as poly(dimethylsiloxane), poly(methylphenylsiloxane), etc.) andalkoxylated derivatives therefrom such as those described in U.S. Pat.No. 5,932,355, incorporated by reference herein, for the description ofalkoxylated derivatives of polysiloxane polymers; hydrolyzable orotherwise condensable silanes such as cyclosiloxanes (e.g.,octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, etc.);alkoxysiloxanes (e.g., octyltriethoxysilane, octadecyltriethoxysilane,octyltrimethoxysilane), acyloxysilanes, hydrosilanes, and the like.

Non-limiting examples of useful polyvinyls include poly(meth)acrylates(i.e., polymerized ethylenically unsaturated monomers) such ashydrocarbyl ester (meth)acrylate polymers (for example, polymers andcopolymers of butyl acrylate, hexyl acrylate, octyl(meth)acrylate,ethyl(meth)acrylate, propyl acrylate, etc.); copolymers of ethylene andvinyl acetate, vinyl chloride, etc.; homopolymers and copolymers ofacrylonitrile; homopolymers and copolymers of styrene.

When additional washfastness is desired, it is possible to incorporate aco-monomer having a thermosettable group such as methylol acrylamideco-monomer into the polyvinyl copolymers. Many such materials areavailable under the RHOPLEX trade designation from Rohm & Haas Co. ofPhiladelphia, Pa.

Dispersed hydrophobic materials are typically applied as aqueoussolutions having from 1-50 weight percent solids, or even higher. Whenused alone, the hydrophobic materials are preferably 5-40 weight percentsolids, more preferably 10-30 weight percent solids dispersions. Whencombined with the mordant and applied as a single dispersion, thedispersed hydrophobic materials are preferably present at 5-30 weightpercent solids.

Method of Making the Invention

The mordants and dispersed hydrophobic materials may be employedindividually or easily mixed and used as a single dispersion. Whenmixed, reasonable care should be taken to avoid an incompatible mixture,as stability for a period of weeks to years is generally desirable.

While the solids content of the mordant solution or dispersion and thedispersed hydrophobic materials components is typically in the rangeslisted above, it may also be important to control the coating weight(i.e., add on) of the coating applied to the substrate. In someembodiments of the invention, the mordant is applied in an amountsufficient to wet the substrate to allow for rapid ink sorption and thenprinted directly on the damp substrate.

For typical porous substrates (e.g., fabrics) a wet add on for themordant is from about 0.1 part up to about 20 parts wet add on per 10parts fabric by weight, preferably from about 0.5 part up to about 15parts wet add on per 10 parts fabric by weight. For hard non-poroussubstrates typical wet add on for the mordant ranges from about 5 gramsper square meter up to about 500 grams per square meter, preferably fromabout 10 grams per square meter up to about 100 grams per square meter,more preferably from about 30 grams per square meter up to about 70grams per square meter. On the other hand, in some embodiments withparticularly absorbent substrates, it may be advantageous to dry themordant. This is because the substrates would contain excess water whichwould decrease the effectiveness of the mordant.

Method of Using the Compositions

The compositions of the invention may be utilized on many types offabrics of many different constructions, including for example, wovenfabrics, knit fabrics, and non-woven fabrics. Examples of fabricsinclude, but are not limited to, those having fibers made frompolyamides such as nylon; polyesters such as DACRON; polyolefins such aspolypropylene, polyethylene, etc.; cotton; linen; wool; and rayon.

In one embodiment, an image is printed or transferred and fixed onfabric. In a first step, the mordant dispersion is first applied to thecloth covering the area to be imaged, and optionally dried. In a secondstep, the image is applied to the treated area, and then the image isoptionally dried. The image may be dried at ambient or room temperature(typically, 20° C.-25° C.) or heated at a temperature of up to 100° C.to dry the image. In a third step, a dispersed hydrophobic material isapplied to the image bearing surface of the substrate, and dried atambient or room temperature (typically, 20° C.-25° C.) or heated at atemperature of up to 100° C. to dry the image with optional heating to atemperature sufficient to remove residual water and optionally causechemical crosslinking of the hydrophobic material. Typically, thisinvolves temperatures of up to about 100° C., although in some cases,higher temperatures may be useful depending on the nature of thecrosslinking chemistry and the substrate. Drying time of the hydrophobicmaterial ranges from about 2 minutes to 24 hours or more, depending uponthe drying temperature.

In another embodiment, the invention provides a method for providing adurable ink image on a substrate, wherein the method comprises the stepsof coating a substrate with a mixture of an aqueous mordant and adispersed hydrophobic material, optionally, drying the coated substrate,printing or transferring a selected image onto the coated surface of thesubstrate, and an optional further step of heating the substrate.

In another embodiment, the invention provides a method for providing adurable ink image on a non-porous substrate. Examples of non-poroussubstrates include polymeric films, painted surfaces such as walls,glass, metals, and the like. The method comprises the steps of coating asurface of a non-porous substrate with an aqueous fluoropolymerdispersion, printing or transferring an image onto the coated non-poroussubstrate, drying, and optionally heating the coated image such that thedispersed fluoropolymer material becomes hydrophobic. The method mayalso optionally include drying the coated fluoropolymer dispersion atpreferably, ambient temperature to 100° C. or more depending on thepolymer. Typical drying times range from 2 minutes to 24 hours or moredepending upon the drying temperature. However, care should be taken notto dry or to allow the aqueous fluoropolymer dispersion to drycompletely to the hydrophobic state prior to applying the image over thecoated dispersion. If the coated dispersion becomes hydrophobic, theimage will not become fixed onto the substrate or may not even form orbe transferred. Thus, prior to image printing or transfer, thehydrophobic material should be dried such that an image can be appliedthrough wetting of the ink.

The various processes of the invention may be carried out with any inkknown in the graphic arts. Preferably, the inks used are based aqueousinks, with the greatest benefit observed when dye based aqueous inks areemployed. Thus, the invention is particularly well suited for us withcommercial inkjet inks such as those available, for example, fromHewlett-Packard Corp. of Palo Alto, Calif., and Lexmark International ofLexington, Ky.

Mordants and dispersed hydrophobic materials used in practice of theinvention may be applied to substrates in a wide variety of methodsknown for coating liquids on substrates. Examples include roll coating,gravure coating, spraying, inkjet printing, bar coating, knife coating,saturation coating methods, sponge coating, and the like.

Mordants and dispersed hydrophobic materials used in practice of theinvention may be dried in a wide variety of methods depending on need.Useful techniques include air drying under ambient conditions, drying ina forced air or convection oven, heat gun, infrared lamps, etc.

Images may be applied to substrates according to the various processesof the invention by any means for imaging with liquid inks known in thegraphic arts. One preferred method for printing images according to theinvention is an indirect transfer process in which the image is printedas a reverse image on an image transfer medium, then transferred to asecond substrate by intimately contacting the image transfer medium withthe second substrate and applying pressure (e.g., with a hand-heldroller, by hand, and the like), and then subsequently removing the imagetransfer medium.

An “image transfer medium” is any medium which is capable of receivingan image and then transferring an image to another substrate. Usefulimage transfer media include sheets having a smooth imaging surface andsheets having a micro-embossed imaging surface. A micro-embossed surfacehas a topography wherein the average micro-embossed element pitch, thatis, center to center distance between micro-embossed elements is fromabout 1 to about 1000 micrometers and average peak to valley distancesof individual micro-embossed elements is from about 1 to about 100micrometers. A “micro-embossed element” means a recognizable geometricshape that either protrudes or is depressed.

FIG. 15 illustrates a preferred embodiment of an image transfer medium10 that is constructed of a sheet 12 having an imaging surfacecharacterized by a micro-embossed image surface topography 14 ofmultiple wells or cavities 16 and peaks 18 and having a coating of anink release material 20. The imaging surface of the sheet is nonporous.“Nonporous” means that the integral imaging surface of the sheet is notsubstantially porous to liquid inks. “Ink release material” means amaterial that provides for the release of not only inks but otherprinted materials as well. The ink release material is used to lower thesurface energy of the micro-embossed image surface, which facilitatesink transfer. “Surface energy” as used herein is equal to the surfacetension of the highest surface tension liquid (real or imaginary) thatwill completely wet a solid with a contact angle of 0 degrees, which maybe determined by measuring the critical surface tension from staticcontact angles of pure liquids using the method of W. A. Zismandescribed in “Relation of Equilibrium Contact Angle to Liquid and SolidConstitution”, ACS Advances in Chemistry Series #43, American ChemicalSociety, 1961, pages 1-51, incorporated by reference herein. The imagetransfer medium 10 is useful for receiving an ink image and protectingthe ink image from abrasion, and then capable of transferring the ink toanother substrate. FIG. 15 also illustrates an ink drop 30 within onecavity 16 such that the outermost surfaces or peaks 18 of themicro-embossed topography, on a macroscopic level, control placement ofthe ink drop 30 before transfer.

Sheet 12 used in the image transfer medium can be made from any polymeror combination of polymers capable of being micro-embossed in the mannerof the present invention.

The ink release coating is a coating that resides on the micro-embossedsurface. The ink release coating may be continuous or discontinuous andis preferably continuous. The purpose or function of the ink releasecoating is to lower the surface energy of the micro-embossed surface ofthe image transfer medium, thereby facilitating a more complete transferof the ink to a second substrate to form an image of high color densityto a second substrate. Without the ink release coating, only portions ofthe image may transfer or only a top portion of the ink contained ineach cavity may transfer to the second substrate, requiring perhaps asecond ink image printed and transferred. Thus, useful ink releasecoatings are those coatings that can be applied or migrate to themicro-embossed surface of the sheet to lower the surface energy of theportions of the cavities which ink will contact such that at least 20percent, preferably at least 50 percent, even more preferably at least75 percent of the ink is transferred as measured by reflectance colordensity.

Preferred ink release coatings include compositions comprisingsilicones, fluorochemicals, and polymers thereof. Alternatively,additives may be incorporated into polymeric materials used for sheetsor surfaces of sheets that migrate to the surface of the image transfermedium and provide a low surface energy coating, that is, ink releasecoating. These additives may be added to thermoplastic and/or thermosetresins that are extruded and micro-embossed to form image transfer mediaof the invention. Useful surface energy modifying additives includesilicone surfactants such as those available from OSi Specialties, Inc.,of Danbury, Conn., under the tradename SLWET, and fluorinatedsurfactants such as those available under the tradename FLUORAD FC-1802,etc., available from Minnesota Mining and Manufacturing Company, St.Paul, Minn.

Preferred ink release coatings provide the micro-embossed surface with asurface energy of about 43 dyne/centimeter or less, preferably about 30dyne/centimeter or less, more preferably about 25 dyne/centimeter orless. Ink release coating materials that will provide surface energiesof 43, 30, and 25 dynes/centimeter or less are commercially available.

In general, the choice of geometrical configuration of the specificmicro-embossed features does not greatly influence image transferperformance, so long as there is sufficient micro-embossed capacity tocontrol placement of an individual drop of ink. In some preferredembodiments, the geometrical configuration is chosen such that themicro-embossed element pitch (i.e., center to center distance betweenmicro-embossed elements) is less than about 340 micrometers. In furtherpreferred embodiments, the micro-embossed micro-embossed element densityof the pattern is such that the cavity walls actually collapse whenmoderate pressure is applied by hand to effect the transfer of theimage.

For example, low density polyethylene walls micro-embossed as anorthogonal grid and having an average wall thickness of 10-25micrometers, spaced with a micro-embossed element pitch of 338micrometers, and having square cavities with a depth of 25 micrometers,completely collapse during image transfer with moderate hand pressure.On the other hand, the same low density polyethylene materialmicro-embossed with an orthogonal grid pattern with walls 10-25micrometers thick, spaced with a micro-embossed element pitch of 127micrometers, and having square cavities with a depth of 25 micrometersdo not collapse.

In general, the amount of ink transferred from films with collapsiblefeatures is superior to those films containing more rigid features.Silicone rubber micro-embossed elements are preferred, since theycollapse under pressure, but quickly recover to their original shapewhen pressure is removed so the film can be used again.

In a preferred embodiment, the micro-embossed imaging surface topologyis chosen so that ink droplets printed onto the micro-embossed surfacedo not protrude above the tops of the micro-embossed elements therebyimproving handling properties of imaged sheet.

In another image transfer medium, shown in FIG. 16, the image transfermedium 40 is constructed of a sheet 42 having an micro-embossed imagingsurface topography 44 of multiple wells or cavities 46 and peaks 48wherein the micro-embossed or image surface has ink release properties.In this embodiment, the micro-embossed imaging surface itself has inkrelease properties, that is, the micro-embossed surface has a surfaceenergy that facilitates the transfer of ink from the surface topographywithout any additional ink release coating added (See FIG. 15). Theimaging surface of the sheet is also nonporous as defined above.

Materials having a surface energy in the range of from about 43dyne/centimeter or less are suitable for use as sheets 42 or as amicro-embossed surface topography 44. Non-limiting examples of materialsthat provide a suitable surface energy include polymeric materials suchas polydimethylsiloxanes, fluorinated polymers, polyolefins (e.g., suchas polyethylene, polypropylene, etc.) and polyvinyl chloride. For usewith aqueous inks, useful materials have a surface energy of less thanabout 43 dyne/centimeter, with materials having a surface energy of fromabout 30 dyne/centimeter or less being preferred. For use withnon-aqueous inks (i.e., solvent based or 100 percent solids), materialshaving a surface energy of from about 30 dyne/centimeter or less areuseful, preferably from about 25 dyne/centimeter or less.

In another image transfer medium, shown in FIG. 17, the image transfermedium 50 is constructed of a sheet 52 having a micro-embossed imagingsurface topography 54 of multiple posts 56. The posts may be anyprotruding geometric shape, for example, circular, oval, trapezoidal,spiral, square, triangular, octagonal, and the like. Preferably, thespace between posts is from about 10 to about 1000 micrometers, evenmore preferably from about 50 to about 800 micrometers and even morepreferably from about 200 to about 600 micrometers. Preferably, theheight of the posts ranges from about 5 to about 100 micrometers, morepreferably from about 10 to about 70 micrometers, even more preferablyfrom about 10 to about 40 micrometers. Preferably, the diameter of theposts ranges from about 10 to about 150 micrometers, more preferablyfrom about 10 to about 100 micrometers and even more preferably fromabout 30 to about 90 micrometers. Preferably, the density of the postsranges from about 1 to about 40 posts per square millimeter, morepreferably from about 2 to about 20 posts per square millimeter and evenmore preferably from about 2 to about 10 posts per square millimeter. Asshown above sheet 52 may be made from a material that provides an inkrelease property to the imaging surface. Alternatively, an ink releasecoating may be coated onto the imaging surface.

In another image transfer medium shown in FIG. 18, the image transfermedium 60 is constructed of a sheet 62 having a micro-embossed imagingsurface topography 64 of wells or cavities 66 and posts 68. The cavitiesare spaced such that they provide control over the placement of the inkdroplets while the posts are spaced to prevent accidental smearing ofthe wet ink. Preferably, the pitch of the cavities is finer than thepitch of the posts. However, the pitch of the cavities when combinedwith the posts can typically be wider than the pitch of cavities alonesince the posts prevent the wet image from smearing during handling. Theposts may also be applied in a random manner to an imaging substratehaving cavities such that some of the posts are within a cavity. Theheight of the posts may or may not exceed the height of the walls of thecavities. As described above, the imaging surface may be constructed ofa material that provides an ink release property of the imaging surfacemay be coated with an ink release coating.

The sheets described in FIGS. 15-18 can be a solid film. The sheets maybe transparent or translucent, clear or tinted, or opticallytransmissive. The sheets 12 and 42 are preferably transparent.

Nonlimiting examples of polymeric films useful as sheets in the imagetransfer media include thermoplastics such as polyolefins (for example,polyethylene, polypropylene, polybutylene, copolymers of styrene andbutadiene, copolymers of ethylene and propylene, etc.); poly(vinylchloride); hydrolyzed or unhydrolyzed copolymers of ethylene with vinylacetate; polycarbonates; norbornene copolymers; fluorinatedthermoplastics such as copolymers and terpolymers comprisinghexafluoropropylene, vinylidene fluoride, tetrafluoroethylene, or vinylfluoride, and surface modified versions thereof, poly(ethyleneterephthalate) and copolymers thereof, polyurethanes, polyimides,acrylics, and filled versions of the above using fillers such assilicates, aluminates, feldspar, talc, calcium carbonate, titaniumdioxide, and the like. Also useful in the application are non-wovens,coextruded films, and laminated films made from the materials listedabove. A person of ordinary skill in the art can easily measure thesurface energy of any of the above films to determine whether the filmsprovide a suitable surface energy for use in an image transfer mediadescribed by FIG. 16 and the accompanying text.

More specifically, polyolefins can be ethylene homopolymers orcopolymers, such as “7C50” brand ethylene propylene copolymercommercially available from Union Carbide Co. of Houston, Tex. Otherspecifically useful films include “LEXAN” polycarbonate from GeneralElectric Plastics of Pittsfield, Mass., “ZEONEX” polymer from B. F.Goodrich of Richfield, Ohio, fluoropolymers such as “THV-500” and “THV250” polymers from Dyneon LLC of Oakdale, Minn., plasticized poly(vinylchloride), poly(ethylene terephthalate) copolymer “EASTAR” 6763 fromEastman Chemical Co. of Kingsport, Tenn., “AFFINITY” PL 1845 from DowChemical Co. of Midland, Mich., and SURLYN™ acrylic acid copolymers fromE. I. Du Pont de Nemours and Co. of Wilmington, Del.

In further embodiments of sheets shown in FIGS. 15-18, any sheetsuitable for feeding into an inkjet printer may be further coated,laminated, or co-extruded with one or more of the polymers suitable foruse in polymeric films of according to the invention and furthermicro-embossed (and, if necessary, coated with an ink release materialas described herein) to provide image transfer media of the invention.Non-limiting examples of such sheets are papers, including for examplexerographic grade papers, specialty inkjet papers, and coated papers,etc.; nonwoven materials, including for example spunbond polyolefins,etc.; card stock; envelopes; etc.

Thermoset materials are also additionally useful as materials for sheetsor micro-embossed imaging surface topographies that have ink releaseproperties without the use of an ink release coating. For example,reactive silicones (either two-part or moisture curable, UV-curablematerials (e.g., acrylate mixtures) may be applied to a micro-embossedroll, cured and removed from the roll to give an micro-embossed filmhaving an inverse image of the roll.

The structure of the micro-embossed surface topography can be anystructure that provides cavities that will each hold at least 10 pL ofink. For example, the topographies for the cavities can range from theextreme of cubic cavities with parallel vertical, planar walls, to theextreme of hemispherical cavities, with any possible solid geometricalconfiguration of walls in between the two extremes. Specific examplesinclude conical cavities with angular, planar walls, truncated pyramidcavities with angular, planar walls, and cube corner shaped cavities.Other useful micro-embossed structures are described in PCT publicationsWO 00/73082 and WO 00/73083.

The pattern of the topography can be regular, random, or a combinationof the two. “Regular” means that the embossing pattern is planned andreproducible regardless of the pattern of the embossing. “Random” meansone or more features of the micro-embossed elements are intentionallyand/or systematically varied in a non-regular manner. Examples offeatures that are varied include for example, micro-embossed elementpitch, peak-to-valley distance, depth, height, wall angle, edge radius,and the like. Combination patterns may for example comprise patternsthat are random over an area having a minimum radius of ten cavitywidths from any point, but these random patterns can be reproduced overlarger distances within the overall pattern.

More than one drop of ink may be contained in a cavity because themixing of the colors cyan, yellow, and magenta are required to createthe infinite number of colors demanded in the inkjet industry. Thus, thevolume of the cavities should be capable of holding as many as threedrops of different colors of ink. The volume of a cavity can range fromabout 1 to about 20,000 pL, preferably from about 1 to about 10,000 pL,more preferably from about 3 to about 1,000 pL, even more preferablyfrom about 30 to about 10,000 pL, and even more preferably from about300 to about 10,000 pL.

For applications in which desktop inkjet printers (typical drop size of3-20 pL) will be used to generate the image, cavity volumes of fromabout 1000 to about 3000 pL are preferred. For applications in whichlarge format desktop inkjet printers (typical drop size of 10-200 pL)will be used to generate the image, cavity volumes of from about 3,000to about 10,000 pL are preferred.

Another way to characterize the structure of the cavities is to describethe cavities in terms of aspect ratios. An “aspect ratio” is the ratioof the depth to the width of the cavity. Useful aspect ratios range fromabout 0.01 to about 2, preferably from about 0.05 to about 1, and morepreferably from about 0.05 to about 0.3.

The overall depth of the cavities depends on the shape, aspect ratio,and desired volume of the cavities. For a cubic-shaped cavity, the depthranges from about 5 to about 100 micrometers. For a hemispherical-shapedcavity, the depth ranges from about 7 to about 100 micrometers. Thedepths of other geometrically shaped cavities reside in between thesetwo extremes for a given volume.

Micro-embossed element pitch of the micro-embossed image transfer mediaof the invention are in the range of from 1 to about 1000 micrometers,preferably from 10 to about 500 micrometers, more preferably from about50 to about 400 micrometers. It is recognized that in some embodimentsof the invention, it may not be necessary, or desirable, that uniformmicro-embossed element pitch be observed between micro-embossedelements, nor that all features be identical. Thus, an assortment ofdifferent types of features, for example, cavities or wells with,perhaps, an assortment of micro-embossed element pitches may comprisethe micro-embossed surface of the image transfer media according to theinvention.

Image transfer media of the invention may be prepared and used in manydimensions. Useful lengths may be from about 1 centimeter up to 2,000meters or even longer (especially when used in roll form). Useful widthsmay be from about 0.5 centimeter up to about 250 centimeters or evenwider. Useful thicknesses of image transfer media of the invention mayrange from about 25 micrometers up to 0.5 millimeter or even higher solong as the material may be printed by inkjet means.

The image transfer media of the invention may also optionally have anink receptive coating on the micro-embossed imaging surface. The inkreceptive coating may comprise one or more layers. The purpose of theink receptive coating is to limit migration of colorant both prior toand after subsequent image transfer. The ink receptive coating may beused on any image transfer media described in this application.

Useful ink receptive coatings are hydrophilic and aqueous ink sorptive.Such coatings include, but are not limited to, polyvinyl pyrrolidone,homopolymers and copolymers and substituted derivatives thereof; vinylacetate copolymers, for example, copolymers of vinyl pyrrolidone andvinyl acetate, copolymers of vinyl acetate and acrylic acid, and thelike, and hydrolyzed derivatives thereof; polyvinyl alcohol, acrylicacid homopolymers and copolymers; co-polyesters such as the VITELco-polyesters available from Bostick, Middleton, Mass.; acrylamidehomopolymers and copolymers; cellulosic polymers; styrene copolymerswith allyl alcohol, acrylic acid, and/or maleic acid or esters thereof;alkylene oxide polymers and copolymers; gelatins and modified gelatins;polysaccharides, and the like, as disclosed in U.S. Pat. Nos. 5,766,398;4,775,594; 5,126,195; and 5,198,306. Vinyl pyrrolidone homopolymers andcopolymers are preferred.

Optionally, the ink receptive coatings may also include additives thatprovide a visual property to the transferred image. Such additivesinclude glitter, glass bubbles, pigments, mica, UV absorbers andstabilizers, etc.

Additionally, the image transfer media of the invention may also haveone or more surfactants coated onto the micro-embossed imaging surface.Examples of useful surfactants include those described in U.S. Pat. No.5,932,355 at column 7, lines 22-31, incorporated by reference in thisapplication.

The transfer medium 10 optionally has an adhesive layer on the majorsurface of the sheet opposite micro-embossed image surface 12 that isalso optionally but preferably protected by a release liner. Afterimaging, the receptor medium 10 can be adhered to a rigid substratebefore image transfer.

The choice of adhesive and release liner depends on usage desired forthe image graphic.

Pressure-sensitive adhesives can be any conventional pressure-sensitiveadhesive that adheres to both the polymer sheet and to the surface ofthe item upon which the transfer medium having the precise image is tobe placed. Pressure-sensitive adhesives are generally described inSatas, Ed., Handbook of Pressure Sensitive Adhesives 2nd Ed. (VonNostrand Reinhold 1989), the disclosure of which is incorporated byreference. Pressure-sensitive adhesives are commercially available froma number of sources. Particularly preferred are acrylatepressure-sensitive adhesives commercially available from MinnesotaMining and Manufacturing Company, and generally described in U.S. Pat.Nos. 5,141,790; 4,605,592; 5,045,386; and 5,229,207; and EPO PatentPublication EP 0 570 515 B1.

Release liners are also well known and commercially available from anumber of sources. Nonlimiting examples of release liners includesilicone coated kraft paper, silicone coated polyethylene coated paper,silicone coated or non-coated polymeric materials such as polyethyleneor polypropylene, as well as the aforementioned base materials coatedwith polymeric release agents such as silicone urea, fluorinatedpolymers, urethanes, and long chain alkyl acrylates, such as defined inU.S. Pat. Nos. 3,957,724; 4,567,073; 4,313,988; 3,997,702; 4,614,667;5,202,190; and 5,290,615; the disclosures of which are incorporated byreference herein and those liners commercially available as POLYSLIKbrand liners from Rexam Release of Oakbrook, Ill., and EXHERE brandliners from P.H. Glatfelter Company of Spring Grove, Pa.

Method of Forming Micro-Embossed Image Surface

The micro-embossed imaging surface can be made from any contactingtechnique such as casting, coating, or compressing techniques. Moreparticularly, micro-embossing can be achieved by at least any of (1)casting a molten thermoplastic using a tool having a pattern, (2)coating of a fluid onto a tool having a pattern, solidifying the fluid,and removing the resulting micro-embossed solid, or (3) passing athermoplastic film through a nip roll to compress against a tool havingthat micro-embossed pattern. Desired embossing topography can be formedin tools via any of a number of techniques well-known to those skilledin the art, selected depending in part upon the tool material andfeatures of the desired topography. Illustrative techniques includeetching (e.g., via chemical etching, mechanical etching, or otherablative means such as laser ablation or reactive ion etching, etc.),photolithography, stereolithography, micromachining, knurling (e.g.,cutting knurling or acid enhanced knurling), scoring or cutting, etc.

Alternative methods of forming the micro-embossed image surface includethermoplastic extrusion, curable fluid coating methods, and embossingthermoplastic layers which can also be cured.

Other specific examples of useful image transfer media include thosedescribed in U.S. Pat. No. 6,153,038.

Depending on the specific formulation and use intended, additionalmaterials may be incorporated into the mordants and/or dispersedhydrophobic materials employed in various aspects of the invention,including adjuvants such as fillers (e.g., glass bubbles, silica, etc.),surfactants, emulsifiers (e.g., water soluble polymers), coating aids,biocides, UV stabilizers, antioxidants, fungicides, optical brighteners,co-solvents (e.g., alcohols, glycols, glycol ethers, etc.), humectants,and the like.

Aspects and advantages of this invention are further illustrated by thefollowing examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention.

EXAMPLES

The following materials and abbreviations are used in the examples thatfollow:

“EPSON STYLUS COLOR” is a trade designation and model for an inkjetprinter, available from U S Epson, Inc. of Torrance, Calif.

“HP51626” black and “C1823” series inkjet inks, “DESKJET PLUS” and“DESKJET 855Cse” thermal inkjet printers are available from theHewlett-Packard Company of San Diego, Calif.

The 100 percent cotton T-shirt cloth used in the examples was HANESSPECIAL-TEE brand, 100 percent combed cotton (white), available fromHanes Companies of Winston Salem, N.C., and had a thickness of 0.203millimeters and basis weight of 104 g/m².

Mayer Rods (i.e., wire-wound rods) are available from R D Specialties,Inc. of Webster, N.Y. # 6 Mayer Rods give coatings of nominal wet filmthickness of 0.014 millimeter.

“FLUORAD FC-359” (an aqueous dispersion of a fluoroalkyl polymer(approximately 20 percent)), “FLUORAD FC-461” (a aqueous dispersion of afluoroalkyl copolymer (approximately 27 percent), “FLUORAD FC-1355” (anaqueous dispersion of a fluoroalkyl polymer (approximately 15 percent)),and “FLUORAD FC-280” (an aqueous dispersion of a fluoroalkyl polymer(approximately 30 percent)) are trade designations for aqueousfluoropolymer dispersions available from Minnesota Mining andManufacturing Company of St. Paul, Minn.

“3M FINE GRADE SANDING SPONGE” was obtained from Minnesota Mining andManufacturing Company.

“ASPEN SELECT GRADE HOBBY WOOD” is a trade designation for aspen wood,which has been sanded smooth for use by hobbyists. It or equivalents maybe obtained at hobby and craft stores.

Alumina-HPMC is an aqueous solution (2.5 percent solids) of an aluminumion-crosslinked hydroxypropyl methylcellulose polymer networkimpregnated with a colloidal aluminum oxide-hydroxide sol as describedin U.S. Pat. No. 5,686,602 using the procedure of Example 1 and the acidof Example 2, incorporated by reference in this application.

“DISPAL 23N4-20” is a 25 weight percent solids aqueous aluminadispersion, available from Vista Chemical Co. of Houston, Tex.

“ERA” is a brand name for laundry detergent, available from Procter andGamble Co. of Cincinnati. Ohio.

“FREESOFT 970” is a trade designation for a silicone emulsion (20 weightpercent solids in water), available from B.F. Goodrich Co. of Akron,Ohio.

“AIRFLEX 465” is an aqueous dispersion of ethylene-vinyl acetatecopolymer (approximately 60 weight percent solids), available from AirProducts and Chemicals, Inc. of Allentown, Pa.

“NALCO 2326” (a colloidal silica sol, 5 nanometer particle size), “NALCO2327”, (a colloidal silica sol, 20 nanometer particle size), “NALCO2329”, (a colloidal silica sol, 75 nanometer particle size), and “NALCO1056” (alumina-coated silica, 20 nanometer particle size), are availablefrom Nalco Chemical Co. of Naperville, Ill.

“AEROSIL A130” is a trade designation for dry fumed silica, availablefrom DeGussa Corp. of Ridgefield Park, N.J.

“3M SCOTCHCAL GRAPHIC MARKING FILM” (a trade designation 0.05 millimeterthickness, white polyvinyl chloride film), and “SCOTCH BRAND MAGIC TAPE”(a trade designation for transparent tape) are both available fromMinnesota Mining and Manufacturing Company.

Silicone coated LDPE/PET/HDPE (i.e., low densitypolyethylene/polyethylene terephthalate/high density polyethylene) filmsurface and polyethylene coated paper each having a thin siliconetopcoat on the LDPE surface, are available from Rexam Release.

Aluminum nitrate, aluminum sulfate, and 3-aminopropyltrimethoxysilaneare available from general chemical vendors such as from AldrichChemical Co. of Milwaukee, Wis.

Micro-Embossed Image Transfer Media

The following microstructured patterns were used in some of theexamples, which follow and are referred to as Pattern 1 and Pattern 2.Both patterns were micro-embossed by calendering of a continuous web ofthe materials to be micro-embossed using a corresponding engraved rollhaving an inverse image as the roll contacting the micro-embossed sideof the web, unless otherwise specified.

Pattern 1 is a “75 LPI” pattern referred to in the examples is an arrayof square cavities that are 25 micrometers deep and having amicro-embossed element pitch of 332 micrometers and walls that are 9micrometers thick at their top and 22 micrometers thick at their base.

Pattern 2 is a “130 LPI” pattern of square cavities of 197 micrometersmicro-embossed element pitch, cavity depth of 15 micrometers, andincluded wall angle of 60°. The wall thickness is 20 micrometers at thebottom of the cavity. Additionally, at the center of the bottom of thiscavity resides a second cavity that increases the total volume of thestructure. This second cavity is pyramid shaped (four sides proceedingto a point at the deepest point of the two-cavity structure). It is 38micrometers wide at the opening, and is 10 micrometers deep with a 125°included angle of descent.

General Procedure a for Preparing Imaged Articles:

A digitally created image stored on a computer was imaged with an EPSONSTYLUS color inkjet printer operating at the 720 dpi, Coated 720×720Media settings onto piece of 0.1 millimeter polyvinylidene dichlorideprimed polyethylene terephthalate film coated with a fluorinated releaselayer (image transfer medium) prepared as described in ComparativeExample 1 of U.S. Pat. No. 5,760,126, incorporated by reference herein.This image, while still wet, was transferred onto 100 percent cottoncloth that had been dampened with an aqueous liquid (wet add on ofapproximately 10 weight percent) by intimately contacting the imagedsurface of the image transfer medium with a printable surface of adesired substrate, applying firm hand pressure to the back side of theimage transfer medium, and removing the image transfer medium. Theresulting wet image was placed in an air convection oven for 5 minutesat 100° C.

Comparative Example 1

This comparative example illustrates the problems associated withimaging cotton cloth using inkjet printer inks.

A 15 centimeter by 15 centimeter piece of cotton cloth was imagedaccording to General Procedure A using deionized water to dampen thecotton cloth. The imaged cloth was placed into a capped vial of water(30 grams of water). The vial was agitated for a minute to wet thecloth, then left to stand at ambient room temperature for about 24hours. The water extract showed significant color, due to the dyesleaching out into the solution. A UV-Vis absorption spectrum was takenof the resulting solution, showing several absorption bands, due to thevarious colors coming out into the solution. The maximum absorption wasfor the magenta color, which has a visible absorption maximum at 560nanometers. The optical density (i.e., absorbance) of the solution at560 nanometers was 1.18. Image quality (i.e., color density andresolution) was badly degraded.

Comparative Example 2

Alumina-HPMC was applied to a cotton cloth with a #6 Mayer Rod and wasimaged according to General Procedure A. The imaged cloth was placedinto a capped vial of water (30 grams). The vial was agitated for aminute to wet the cloth, then left to stand at ambient room temperaturefor about 24 hours. The water extract showed less color due to the dyesleaching out into the solution than seen in Comparative Example 1.

The optical density of the solution at 560 nanometers was 0.40. Theimage quality was much better than was that of Comparative Example 1before and after soaking in water.

Comparative Example 3

A water-based dispersion of fluoropolymer, FLUORAD FC-359, was appliedto a cotton cloth with a # 6 Mayer Rod. An image was applied and theresulting image dried according to General Procedure A.

The imaged cloth was placed into a capped vial of water (30 gramswater). The vial was agitated for a minute to wet the cloth, then leftto stand at ambient room temperature for about 24 hours. The waterextract showed less color due to the dyes leaching out into the solutionthan seen in Comparative Example 1.

The optical density of the solution at 560 nanometers was 0.68. Theoverall image was better quality than that of Comparative Example 1, butpoorer than the image of Comparative Example 2 after soaking in water.

Comparative Example 4

A 10 percent solution of aluminum nitrate in water was applied to cottoncloth (T-shirt) with a #6 Mayer Rod. This cloth was imaged by GeneralProcedure A. The dried imaged cloth was placed into a vial of water.After some agitation, immediately the solution became colored. Theoptical density of the solution was greater than 2, with very littleimage apparent on the cloth.

A repeat of this procedure using aluminum sulfate in place of aluminumnitrate gave the same result.

Example 1

This is an illustrative example of an image fixing treatment accordingto the invention.

A solution was made of the following ingredients:

alumina-HPMC solution 5 parts by weight FLUORAD FC-359 1 part by weight

The resulting 3 percent (by solids) aqueous solution was mixed well andapplied to cotton cloth with a # 6 Mayer Rod. A piece of cotton clothwas coated with the above composition using a # 6 Mayer Rod and wasimaged according to General Procedure A. The imaged cloth was placedinto a capped vial of water (30 grams of water). The vial was agitatedfor a minute to wet the cloth, then left to stand at ambient roomtemperature for about 24 hours. The water extract showed much less colordue to the dyes leaching out into the solution than seen in ComparativeExample 1.

The optical density of the solution at 560 nanometers was 0.23. Theimage quality was better than that of the image of Comparative Examples2 and 3 after soaking in water.

Example 2

These are illustrative examples of image fixing treatments according tothe invention.

A number of examples were performed using the same two ingredients as inExample 1 in differing ratios. Examples were carried out as previouslydescribed in Example 1, and the images tested for colorfastness asbefore, except that the coatings were sprayed with a aerosol dispenser(wet add on weight was in the range of 100-140 grams per square meter).

TABLE 1 Alumina- FLUORAD Absorbance at HPMC FC-359 560 Nanometers(Weight (Weight of Water Example No. Percent) Percent) Solution 2a 95 50.34 2b 90 10 0.32 2c 83.3 16.7 0.23 2d 75 25 0.12 2e 50 50 0.06 2f 3070 0.38

Examples 3a-3d

These are illustrative examples of an image fixing treatment accordingto the invention.

Weight ratios of 5 parts of alumina-HPMC to 1 part of the fluoropolymerwere used. The procedure of Example 2 was repeated using the materialsand amounts described in Table 2, and the images tested forcolorfastness as before. Results are presented in Table 2.

TABLE 2 Alumina- HPMC Fluorinated Absorbance at 560 (Weight AdditiveNanometers of Water Example No. Percent) (Weight Percent) SolutionComparative 0 0 1.18 Example 1 3a 83.3 FLUORAD FC- 0.23 359, 16.7 3b83.3 FLUORAD FC- 0.12 461, 16.7 3c 83.3 FLUORAD FC- 0.50 1355, 16.7 3d83.3 FLUORAD FC- 0.26 280, 16.7

Example 4

These are additional illustrative examples of image fixing treatmentsaccording to the invention.

Instead of alumina-HPMC, DISPAL 23N4-20 (a commercially availableaqueous alumina dispersion) was used. This was mixed with fluoropolymer,then coated with a # 6 Mayer Rod onto the cloth to dampen the cloth. Thecomposition contained a ratio of 4.7 parts DISPAL 23N4-20 to 1 part ofFLUORAD FC-461. An image was applied and the resulting image dried as inGeneral Procedure A. The water soak test of Example 3 was carried out onthese samples, with the exception that a 0.1 percent commercial laundrydetergent (ERA brand) in water solution was used to test the imagedfabric. The result obtained with this test was an optical density at 560nanometers of 0.013. Other ratios varying from 10:1 down to 2:1 byweight of DISPAL 23N4-20: FLUORAD FC-461, also gave good image qualityafter soaking in water for 24 hours.

Example 5

This is an illustrative example of an image fixing treatment accordingto the invention.

A solution was made with AIRFLEX 465 latex polymer and DISPAL 23N4-20(each component is 50 percent by weight in the final solution, which is30 percent solids in water). A cotton cloth was coated with thissolution using a #6 Mayer Rod, then subsequently imaged as inComparative Example 1 while still damp. Detergent resistance wasmeasured as in Example 4. The optical density of the colorant insolution at 560 nanometers was 0.15.

A solution was made containing 3 parts alumina-HPMC to 4 parts of theAIRFLEX 465 (solution is 16 percent by weight). A cotton cloth wascoated with this solution using a #6 Mayer Rod, then subsequently imagedas in Comparative Example 1 while still damp. Detergent resistance wasmeasured as in Example 4. The optical density of the colorant insolution at 560 nanometers was 0.21.

Example 6

This example demonstrates the utility of using FLUORAD FC-359 as anaqueous inkjet ink receptive coating for a nonporous polyvinyl chloridefilm with subsequent heating to provide a water repellent finishedprint.

A piece of 3M SCOTCHCAL GRAPHIC MARKING FILM was coated with FLUORADFC-359 at ambient temperature using a #16 Mayer Rod. The coating wassubsequently dried at ambient temperature for two hours. After drying,the coated film was printed upon with black ink (HP51626 black inkjetink), using a DESKJET PLUS inkjet printer operating in standard mode.The test pattern consisted of black text.

After printing, the ink was observed to feel dry to the touch in a fewminutes. At this time, the printed substrate was placed in an oven at100° C. for two minutes. After heating, the substrate was found to berepellent to aqueous and oily fluids. Using the protocol described inthe American Association of Textile Chemists and Colorists (AATCC)Standard Test Method No. 118-1983, which is a test based on theresistance of a fabric to penetration by oils of varying surfacetensions, a static oil repellency rating of 7 (i.e., excellent) wasobtained. Oils and their associated rating numbers are shown in Table 3below.

TABLE 3 AATCC Oil Repellency Rating Number Oil 1 mineral oil C 85:15mineral oil:n-hexadecane 2 65:35 mineral oil:n-hexadecane 3 n-hexadecane4 n-tetradecane 5 n-dodecane 6 n-decane 7 n-octane 8 n-heptane

Using the same static repellency test, but substituting water,isopropanol, and mixtures thereof, aqueous repellency ratings weredetermined as shown in Table 4. After soaking in water minutes, partialrelease of the ink was observed. The source of the weakening of thecoating appeared to be at the edges, where encroachment of water couldbe seen after several minutes.

TABLE 4 Aqueous Repellency Rating Number Liquid 0 water 1 90 partswater/10 parts isopropanol (wt/wt) 2 80 parts water/20 parts isopropanol(wt/wt) 3 70 parts water/30 parts isopropanol (wt/wt) 4 60 partswater/40 parts isopropanol (wt/wt) 5 50 parts water/50 parts isopropanol(wt/wt) 6 40 parts water/60 parts isopropanol (wt/wt) 7 30 partswater/70 parts isopropanol (wt/wt) 8 20 parts water/80 parts isopropanol(wt/wt) 9 10 parts water/90 parts isopropanol (wt/wt) 10 isopropanol

When transparent tape (SCOTCH BRAND MAGIC TAPE) was manually appliedwith pressure against the printed side of the substrate, no adhesion wasobserved. Also, the coating appeared to adhere well to the substrate asfingernail scratching did not remove the coating of the printedcharacters.

Preparations of Compositions 1a-1e

This example shows the improvement in image fixing ability achieved byblending cationically functionalized inorganic particulates withfluorocarbon materials.

NALCO 2327, and NALCO 2329 colloidal silica sols wereamine-functionalized on their surface by reaction with3-aminopropyltrimethoxysilane as follows:

Each collidal silica sol was diluted as necessary to achieve 5-10percent solids by weight and the pH was reduced to 3.5-4 by addition ofa suitable amount of concentrated acetic or sulfuric acid. An amount of3-aminopropyltrimethoxysilane (hereinafter denoted as APTMS) was addedto a separate aliquot of water; and the pH was adjusted to match that ofthe dispersion before its addition to the dispersion with good mixing;the mixture was then stirred and heated to 50° C.-90° C. for 16 hours.The amount of APTMS added, which is shown in the Table 5, was based onthe theoretical surface area of the colloid.

TABLE 5 APTMS (millimoles/gram Composition Silica SiO₂) 1a (comparative)NALCO 1056 0 (diluted to 5-10 percent solids at pH = 4 1b NALCO 2326 1.51c NALCO 2327 0.9 1d NALCO 2329 0.35

Fumed silica (AEROSIL A130) was also reacted with APTMS in the followingmanner:

AEROSIL A130 was dispersed in toluene at 3 percent solids, and atheoretical excess of APTMS (1.4 gram APTMS per gram SiO₂) added to thedispersion. The mixture was refluxed for 16 hours. The silica wasfiltered away from the solvent and washed two times with methanol,followed by refluxing in methanol for at least 24 hours before a finalfiltration and drying of the solids in vacuo. Coating samples were madefrom this material by simple dispersion of the silica in water at pH ofabout 4 (referred to hereinafter as Composition 1e).

Samples for printing, printing operations, and analysis of the printswere generated as described in Example 6 above. In each case, anadmixture of the coating components in water was blended immediatelybefore coating.

Compositions 1a and 1c-1e were blended, respectively, with FLUORADFC-359 in ratios shown in the table below. Each of these admixtures wascoated onto the PVC substrate as used in Example 6, with a #16 MayerRod. Drying was accomplished over 2 hours at ambient temperature, atwhich the film was printed and heated in an oven at 100° C. for twominutes. Imaging behavior, appearance and repellency of the substrateafter printing and heating is compared in Table 6.

TABLE 6 AATCC Oil Aqueous Appearance Repellency Repellency InorganicBlend Ratio of Printed Image After Rating Rating ComponentInorganic:FC-359 Properties Heating Number Number Composition 1:1 Dry in2-3 min. Glossy, 7 10 1b Good image smooth resolution Composition 1:1Dry in 2-3 min. Glossy, 7 10 1c Good image smooth, resolution slightyellowing Composition 1:1 Ink beaded up; Glossy, not  0 1a poor drying,smooth, measured poor image slight quality yellowing Composition 5:1Better ink Glossy, not  0 1a wetting but ink smooth measured bled, drytime was poor Composition 2:1 Dry in 2-3 min. Glossy, 7 10 1d Good imagesmooth resolution Composition 1:1 Good drying, Chalky, not  0 1eresolution; ink matte measured was faded in appearance appearance

The following examples show the effectiveness of fixing agents of theinvention when used with inkjet printing onto cotton fabric.

Example 7

A blend of 95 parts DISPAL 23N4-20 and 5 parts FREESOFT 970 was preparedand adjusted with deionized water to 20 weight percent solids. A sampleof cotton material (T-shirt type) was sprayed with this blend (100weight percent wet add on). The treated fabric was imaged by GeneralProcedure A, except that the drying was done at 65° C. for 15 minutes,and the printer used was an DESKJET 855Cse (presentation quality/glossypaper settings) thermal inkjet printer. The image was allowed to dry atambient room temperature for 24 hours before a micrograph was taken.Results are shown as magnified digital images designated FIGS. 1 and 2.

Comparative Example 5

Comparative Example 5 was a sample of cotton material (T-shirt type)sprayed with water (100 weight percent wet add on) and imaged accordingto Example 7. The image was allowed to dry at ambient room temperaturefor 24 hours before a micrograph was taken. Results are shown asmagnified digital images designated FIGS. 3 and 4.

Examples 8a-8f

Blends of the DISPAL 23N4-20 sol were made with FREESOFT 970 andadjusted to 20 weight percent solids with deionized water, then sprayedonto cotton T-shirt cloth. The treated fabric was imaged as in Example7.

The imaged cloths were immersed in a 0.1 percent ERA detergent solutionfor 24 hours. Optical density at 565 nanometers of the detergentsolution (a measure of dye wash out) was measured.

TABLE 7 DISPAL 23N4-20/ Wet add on FREESOFT 970 (Weight Absorbance atExample No. (Weight/Weight) Percent) 565 Nanometers 8a 95:5  100 0.19 8b90:10 100 0.12 8c 90:10 50 0.46 8d 90:10 200 0.06 8e 80:20 100 0.17 8f60:40 100 0.1

Example 8b was repeated, with the imaged cloth allowed to dry at ambientroom temperature (22° C.) for 24 hours, rather than the above dryingconditions. The same soak test gave a final result of 0.05 as theoptical density at 565 nanometers.

Examples 9a and 9b

This example demonstrates utility of the invention for printing woodensubstrates. ASPEN SELECT GRADE HOBBY WOOD was sanded with a 3M FINEGRADE SANDING SPONGE before addition of fixing agent. The fixing agentused was a combination of 95 weight percent DISPAL 23N4-20 and 5 weightpercent FREESOFT 970 and diluted with water. The aqueous mixture (20percent total solids) was sprayed onto one side of the wood to give anaverage wet coating weight of 50 g/m².

A test pattern consisting of adjacent colored blocks of cyan, magenta,yellow, black, red, green, and blue along with narrow lines of thesecolors crossing color bars were printed onto a polyethylene coated paperhaving silicone topcoat using a Hewlett-Packard DESKJET 855Cse thermalinkjet printer in presentation quality/glossy paper mode. The inked sideof the image transfer medium was subsequently placed in intimate contactwith the treated aspen prepared above, and sufficient pressure appliedto cause transfer of the image to the wood (Example 9a) as shown inmagnified digital image designated FIG. 5.

A second transfer was carried out in the same manner except that theimage transfer medium further comprised a micro-embossed topography(Pattern 1) on the surface of the polyethylene coated paper having asilicone topcoat as shown in magnified digital image designated FIG. 6.

The resulting transferred images clearly showed differences inresolution attributable to the presence or absence of micro-embossedtopography used to affect the transfer of ink to the wood surface. Ascan be seen in magnified digital images, FIGS. 5 and 6, the transferredimage from the smooth film is prone to show where the ink beaded up, rantogether in an uncontrolled fashion, and/or smeared before or duringtransfer. By comparison, the image transferred by the film having amicro-embossed topography has good resolution and ink placement.

Machine Wash Test Procedure

Imaged cloth samples were combined with 1.9 kg of cotton fabric sheetsand placed into a SEARS AUTOMATIC WASHER (1996 Model obtained from Sears& Roebuck Co. of Chicago, Ill.). WISK ULTRA detergent (35 gramsavailable from Unilever United States, Inc. of New York, N.Y.) was addedto the combined load and the normal wash mode cycle was initiated(41+/−2° C., 12 minute cycle).

The washed samples were dried together with the ballast load in a SEARSTUMBLE CLOTHES DRYER (1996 Model year, obtained from Sears & RoebuckCo.) using the medium heat cycle setting (65+/−5° C. for a duration of45 minutes.

Comparative Examples 6-8 and Example 10

These examples demonstrate the advantage of using image fixing agentsaccording to the present invention.

Cotton T-shirt cloth (Hanes Special-Tee brand) was cut into test patchesof approximately 22 centimeters by 14 centimeters and sprayed withaqueous treatments at 100 percent wet add on by weight (i.e., the wetarticle weight was twice that of the original dry weight).

The coated cotton test patches of Comparative Examples 6-8 and Example10 below were imaged as follows: a polyethylene coated paper having asilicone topcoat micro-embossed with Pattern 1 was printed using anDESKJET 855Cse thermal inkjet printer (presentation quality/HP glossypaper settings) with a test pattern containing both solid blocks ofcolor and lines of color through color bars. The inked sheet wasimmediately applied to the damp fabric with moderate hand pressure forabout 1 minute, such that the ink transferred to the fabric. Each fabricsample was placed in a 65° C. oven for 15 minutes, then allowed to standovernight before taking measurements of reflectance optical densities.FIGS. 7-10 are magnified digital images corresponding to heat treatedunwashed cloths from Comparative Examples 6-8 and Example 10,respectively.

The samples were then washed according to the Machine Wash TestProcedure. FIGS. 11-14 are magnified digital images corresponding towashed and dried cloths from Comparative Examples 6-8 and Example 10,respectively. The areas of the cloths shown in FIGS. 11-14 correspond tothe same regions shown in FIGS. 7-10, respectively.

Comparative Example 6

Water was sprayed onto a cotton test patch at 100 percent wet add on byweight. FIG. 7 shows a magnified digital image of the resultant imageafter image transfer. FIG. 11 shows a magnified digital image of thecloth after machine wash. Reflectance optical density measurements forthe imaged samples prior to the Machine Wash Test Procedure and afterthe Machine Wash Test Procedure were:

Black Magenta Cyan Yellow Before machine wash test 0.99 1.16 1.11 0.86After machine wash test 0.57 0.80 0.67 0.02

Comparative Example 7

A solution of DISPAL 23N4-20 alumina sol (20 percent solids in water)was sprayed onto a cotton test patch at 100 percent wet add on byweight. FIG. 8 shows a magnified digital image of the resultant imageafter image transfer. FIG. 12 shows a magnified digital image of thecloth after machine wash. Reflectance optical density measurements forthe imaged samples prior to the Machine Wash Test Procedure and afterthe Machine Wash Test Procedure were:

Black Magenta Cyan Yellow Before machine wash test 0.68 1.19 1.19 0.91After machine wash test 0.49 0.48 0.65 0.05

Comparative Example 8

FREESOFT 970 silicone emulsion (20 percent solids in water) was sprayedonto a cotton test patch at 100 percent wet add on by weight. FIG. 9shows a magnified digital image of the resultant image after imagetransfer. FIG. 13 shows a magnified digital image of the cloth aftermachine wash. Reflectance optical density measurements for the imagedsamples prior to the Machine Wash Test Procedure and after the MachineWash Test Procedure were:

Black Magenta Cyan Yellow Before machine wash test 0.94 1.25 1.23 1.12After machine wash test 0.86 0.81 0.75 0.17

Example 10

A composition of 80 percent by weight of a solution of DISPAL 23N4-20alumina sol (20 percent solids in water) and 20 percent by weightFREESOFT 970 silicone emulsion (20 percent solids in water) was sprayedonto a cotton test patch at 100 percent wet add on by weight. FIG. 10shows the resultant magnified digital image after image transfer. FIG.14 shows a magnified digital image of the cloth after machine wash.Reflectance optical density measurements for the imaged samples prior tothe Machine Wash Test Procedure and after the Machine Wash TestProcedure were:

Black Magenta Cyan Yellow Before machine wash test 0.78 1.26 1.16 1.01After machine wash test 0.56 0.55 0.71 0.20

Example 11

A piece of ASPEN SELECT GRADE HOBBY WOOD was prepared as described inExample 9. A 25 weight percent solids dispersion of DISPAL 23N4-20 wassprayed onto a surface of the wood with a wet coating weight of 51 g/m².The coated wood was then dried at a temperature of 80° C. for 2 minutes.An image was printed onto a Pattern 2 micro-embossed silicone coatedLDPE/PET/HDPE film using a DESKJET 855Cse (presentation quality/HPglossy paper settings) thermal inkjet printer. The image was transferredto this article as described in Example 10. The resulting imaged articlewas placed in an 80° C. oven for 2 minutes. A 21 weight percent solidsdispersion of FREESOFT 970 was sprayed over the image at a coatingweight of 60 g/m². The article was then dried for 10 minutes at 80° C.

The resulting image was bright and showed good resolution. Applicationof water from a deionized water bottle did not wash the image off.Soaking the image in water for 72 hours resulted in aminor loss of colordensity.

1. A method of providing a durable image on a substrate comprising thesteps of: coating a surface of the substrate with an aqueous mordantdispersion; printing or transferring a selected image onto the coatedsurface; optionally drying the image; applying a dispersed hydrophobicmaterial onto the image; and drying the dispersed hydrophobic material.2. The method of claim 1 further comprising the step of heating thesubstrate above ambient temperature after the step of drying thedispersed hydrophobic material.
 3. The method of claim 2 wherein thesubstrate is heated until the dried hydrophobic material becomeshydrophobic.
 4. The method of claim 1 wherein the aqueous mordantdispersion is selected from aqueous dispersions of mordants selectedfrom the group consisting of polymeric dye mordants, inorganic metalcontaining colloids, polymer bound metal ion containing colloids, andcombinations thereof.
 5. The method of claim 1 wherein the selectedimage is transferred onto the coated surface.
 6. The method of claim 5wherein the image is transferred using a micro-embossed image transfermedium.
 7. The method of claim 1 wherein the dispersed hydrophobicmaterial is selected from dispersions of hydrophobic materials selectedfrom the group consisting of fluoropolymers, silicones, polyvinyls,polyesters, polyurethanes, and combinations thereof.
 8. The method ofclaim 1 wherein the aqueous mordant dispersion is dried prior toprinting or transferring the image.
 9. The method of claim 8 wherein theaqueous mordant dispersion is dried at a temperature of 100° C. or less.10. The method of claim 8 wherein the aqueous mordant dispersion isdried at ambient temperature.
 11. The method of claim 1 wherein thedispersed hydrophobic material is dried at a temperature of 100° C. orless.
 12. The method of claim 1 wherein the dispersed hydrophobicmaterial is dried at ambient temperature.
 13. The method of claim 1wherein the image is dried at a temperature of 100° C. or less.
 14. Amethod of providing a durable image on a substrate comprising the stepsof: coating a surface of the substrate with a mixture comprising anaqueous dispersion of a mordant and a dispersed hydrophobic material;printing or transferring an image onto the coated substrate; and dryingthe image and the coated mixture of dispersed mordant and hydrophobicmaterial.
 15. The method of claim 14 further comprising the step ofheating the substrate above ambient temperature.
 16. The method of claim14 wherein the image is transferred using an image transfer medium. 17.The method of claim 16 wherein the image transfer medium is amicro-embossed image transfer medium.
 18. The method of claim 14 whereinthe image and said coated mixture is dried at a temperature of 100° C.or less.
 19. The method of claim 14 wherein the image and said coatedmixture is dried at ambient temperature.
 20. The method of claim 14wherein the aqueous mordant dispersion is selected from aqueousdispersions of mordants selected from the group consisting of polymericdye mordants, inorganic metal containing colloids, polymer bound metalion containing colloids, and combinations thereof.
 21. The method ofclaim 14 wherein the dispersed hydrophobic material is selected fromdispersions of hydrophobic materials selected from the group consistingof fluoropolymers, silicones, polyvinyls, polyesters, polyurethanes, andcombinations thereof.